a) Field of the Invention
The present invention relates to a system, apparatus and method for testing elongate objects, such as pipe, and is directed toward the problem of detecting corrosion, defects or other anomalies to the pipe under conditions where access and/or visual inspection of the pipe is either not possible or impractical.
b) Background Art
In petroleum processing and petrochemical plants and other industrial environments, it is common to have numerous pipes extending between various locations in the plant, with these pipes carrying fluid or gas (e.g.petroleum products), often under high heat and pressure. These pipes are commonly made of steel, and can have an inside diameter ranging anywhere from two to sixty inches, or even outside of this range. The exterior of these pipes are often insulated, with the insulating layers being as great as approximately 1/8 to 5 inches in thickness, or outside of this range.
For a number of reason, (safety, environmental considerations, avoiding costly shut-downs, etc.), the integrity of these pipes must be maintained. Defects in the pipe can occur for a number of reasons. One is that moisture can collect between the insulating layer and the pipe, thus causing corrosion (i.e.rust). Visual inspection of the steel pipe that is encapsulated in insulation is not possible unless the layers of insulation are removed, and then replaced. However, this is expensive and time consuming, and as a practical matter it would be economically unfeasible to accomplish the inspections with reasonable frequency.
It is the object of the present invention to provide a means of inspecting pipes under the circumstances given above in a manner that corrosion, other defects and/or anomalies can be detected with a relatively high degree of reliability, and in a manner that the various difficulties of inspection, such as those mentioned above, can be diminished and/or alleviated.